[OSSTEST PATCH v14 PART 2 10-26/26] Nested HVM testing

[Ian Jackson <ian.jackson@eu.citrix.com>]

This is the second part of v14 Robert Ho's osstest patch series to
support nested HVM tests.

It is also available here:
  git://xenbits.xen.org/people/iwj/xen.git
  http://xenbits.xen.org/git-http/people/iwj/xen.git
in wip.nested-hvm.v14.part1..wip.nested-hvm.v14

Compared to Robert's v13, which was passed to me by private email,
 * I have rebased onto current osstest pretest;
 * I have changed how selecthost() is told it's dealing with
   a nested host (in practice, L1 guest);
 * There are a large number of minor cleanups;
 * There are some new preparatory cleanup and admin patches;
 * I have rewritten almost all of the commit messages.

However, I have done only VERY LIMITED testing.  Much of the code here
is UNTESTED since my changes.  My testing was confined to:
 * Verifying that my changes to cs-adjust-flight worked
 * Checking that ad-hoc runs of ts-host-reboot and ts-host-powercycle
   seemed to work when a guest was specified on the command line.

Robert, you kindly volunteered to test a revised version of this
series.  I would appreciate if you would check that all of this still
works as you expect.  I expect there will be some bugs, perhaps even
very silly bugs, introduced by me.

I noticed that this series lacks guest serial debug keys and log
collection for the L1 guest, because there is no
Osstest/Serial/guest.pm.  I would appreciate it if you would provide
one.  I don't think it needs to actually collect any logs, because the
L1 serial output log will be collected as part of the L0 log
collection.  But it ought to support sending debug keys to the L1
guest.  When you have provided it you can (in the same patch) fix the
corresponding `todo' in selecthost, changing `noop' to `guest'.


Workflow:

Robert: I'm handing this (what I have called `part 2') over to you
now.

When you make changes, feel free to either rebase, or to make fixup
commits (perhaps in `git-rebase -i --autosquash' format) on top.  If
you do the latter then you'll probably want to pass that to me as a
git branch (via git push to xenbits or emailing me a git bundle),
since `squash!' and `fixup!' commits don't look good in email :-).

If you rebase, please put changes
   v15: <description of what you did>
in the commit messages, as I have done myself in v14.  Leave my v14
notes in place.

Of course if you have any comments or queries about how I have done
things, they would be very welcome.

Please do not rebase any of the commits in wip.nested-hvm.v14.part1.
If you discover bugs in `part 1' please let us know as I have fed that
into the osstest self-test mill with the expectation that it will go
into production.

I do not expect you to test the changes to cs-adjust-flight.  I have
done that.  Indeed they are not really related to the Nested HVM work
and Ian C and I may pick them up in another series.


Ian Campbell: You probably want to defer re-reviewing this until
Robert reports back.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>